Actually, both the ways you describe don't work. Observing other dancers is not helpful unless you already have a mental framework to know what you should be observing. Learning to dance by being told steps is ineffective because it doesn't teach you how to actually interact with other dancers, maintain flow, handle the unexpected, or feel where your body mechanics are.

Based on teaching a lot of people to dance and watching a lot of other teaching, the most effective thing I have found is to put someone in a practice dance hold (both people's arms on the other's shoulders, mostly straight) and sway back and forth until they start to feel body connection. Then start to change the magnitude of the sway, make a few simple steps with no warning, just keeping them rooted in the kinesthetic sense of connection. And when that connection is strong enough, bring them into close hold and just start into a waltz. I will have to massively overcompensate on turns initially because they don't know how to do them, but after a few turns around the room, they're ready for that correction. Left turns don't happen that first time out. Then take them contradancing, where they will be guided through interactions among lots of dancers and given a feel for flow. Add something like Renaissance or Scottish low country and you get step work. Only at this point is it useful to start observing other dancers or being told things.

> I can learn dancing by observing other dancers

You could always tell the self-taught ones. Their mental image of what their dance looked like did not match what others saw. That's because what you think you see is not what the actual movement is.

I know it's hard to believe, but it's true. A lot of dance movement is awkward and contorted, but it looks natural and fluid.

You actually learned dancing by having someone telling you the steps? What dance exactly, and how did they explain the steps? What skill level did you achieve?

I thought most people learn dancing by someone telling them the steps. At least in ballroom dancing. How do they explain the steps? "left, left, right, 1,2,3,4 turn" or similar. I never got really good but I think was a competent dancer.

In any case, this thread is not fun anymore. Either I am totally weird or there is some communication going wrong.

> I thought most people learn dancing by someone telling them the steps.

No. Most people learn dancing by watching and repeating, with some explanation along with it.

> At least in ballroom dancing. How do they explain the steps?

In large part by demonstration (there's description that goes along, but the demonstration is primary.) Source: I've nearly completed a long course of instruction for ballroom dance teachers, from a well-regarded teacher-of-teachers, and have taken lots of ballroom dance classes, some from internationally-recognized teachers.

> "left, left, right, 1,2,3,4 turn" or similar.

That's more how they cue students going through a pattern that's been demonstrated than how they explain a pattern. You can explain a pattern in words without demonstration (manuals do this, for instance), but that's usually done as reference material that accompanied traditional teaching-by-demonstration (or, for auto-didacts, videos in place of in-person demonstration), and it sucks on its own; you need a lot of contextual knowledge to get value out of it.

Teaching dance by steps is like teaching racing by telling the student to turn left 4 times each lap.

Nobody fully learns dancing by either of those methods. To be a dancer, one must learn dance by dancing.